Reduced emission combustion process with resource conservation and recovery options &#34;ZEROS&#34; zero-emission energy recycling oxidation system

ABSTRACT

A system and a process for combusting hydrocarbons to recover energy and the carbon dioxide resulting from the combustion is provided. The process utilizes a two-stage combustion process, each stage utilizing water injection and a recirculation stream to increase the efficiency of combustion to generate larger proportions of carbon dioxide. An energy recovery boiler is used to recover heat energy from the combustion product. Combustion product is then cleaned and the carbon dioxide is separated and condensed into a useable liquid carbon dioxide product.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a system and a method for combustinghydrocarbon streams. More specifically, this invention relates to asystem and a method of combusting hydrocarbon streams to recover energythat also maximizes the amount of carbon dioxide produced duringcombustion and provides for recovery of the carbon dioxide produced.

2. Description of the Prior Art

Combustion processes have for millions of years been mankind's mostcommon and essential means of releasing energy for comfort andpreparation of food. In recent times those same processes haveadditionally become essential for transportation, industrial commerce,and the disposal of organic refuse. With an increasing worldwidepopulation and an increased per capita demand for energy, concern is nowbeing raised over the environmental pollution resulting from theemission of gaseous byproducts from combustion processes. Even carbondioxide, a gaseous compound produced during combustion by oxidation ofcarbon and essential to plant life, is being viewed as a pollutanttoday. Carbon dioxide has been identified as one of many "greenhouse"gases and an increased level in the earth's atmosphere is thought likelyto contribute to an undesirable global warming effect. No more thantwenty years ago the scientific community was concerned that the earth'satmosphere was cooling and progressing toward the next "ice age".Obviously some confusion continued to exist along with a lack ofcomplete understanding of the many factors involved in the thermalenergy balance of the earth's crust and the gases comprising the earth'satmosphere. We do understand enough to know that measurable changes inthe composition of the earth's atmosphere will produce added risk ofundesirable changes to the global climate. Until we do completelyunderstand the effects of certain ongoing changes we should attempt tomoderate or even stop those changes from occurring where we can exercisecontrol.

Carbon dioxide production from combustion processes can only be reducedby reducing the level of combustion or converting from carbon containingfuels to fuel such as pure hydrogen. When electrical energy isabundantly available from controlled nuclear fusion or the like,hydrogen fuel can be produced for combustion by electrolysis of water.In the meantime it is essential that we learn to be more conservativewith our use of energy from combustion, make good use of usablecombustion byproducts and limit to the best of our ability the emissionof undesirable and harmful byproducts from the combustion processesemployed for our comfort and well being.

Carbon dioxide is a usable byproduct of the combustion of hydrocarbonfuels. Today most carbon dioxide from combustion processes is releasedinto the atmosphere. The rate of production and release has surpassedthe ability of existing plant life on earth to utilize and the level ofcarbon dioxide in the atmosphere is known to be increasing. Concernsover the effects of an increase "greenhouse" effect due to the increasedcarbon dioxide level in the atmosphere dictate that we do as many thingsas practical to slow or stop the increase in carbon dioxide level in theearth's atmosphere. One method of control is to capture, liquefy andbeneficially utilize carbon dioxide from combustion processes. Among themany beneficial uses of carbon dioxide are enhanced yields from oilwells, detoxification of substances contaminated by hazardoushydrocarbons, fire suppression, food preservation and enhanced growthand production from plants in greenhouses.

SUMMARY OF THE INVENTION

Combustion processes can be configured and operated in a manner whichoptimizes the ability to recover carbon dioxide as a usable byproduct.The invention described here is a combustion process configured tooptimize carbon dioxide recovery. The process additionally lends itselfto extreme limitations on the production of undesirable and harmfulcombustion byproducts while providing the means to control the emissionof those harmful byproducts. Under optimum conditions the process can beconsidered emission-free.

The invention is a combustion process which maximizes the ratio ofcarbon dioxide level to the level of all other combustion gasconstituents in the post combustion chamber gas stream and facilitatesthe efficient capture and liquefication of the carbon dioxide producedby the hydrocarbon fuels combustion process for use as a commercialproduct. When optimally employed the process yields only carbon dioxide,water vapor and oxygen as constituents of the combustion gas stream. Allof these constituents may be segregated, captured, contained and reusedin the process, filtered and discharged as liquid or sold to otherinterests as a commercial product for beneficial use. In less thanoptimum applications the hydrocarbon fuels being combusted might containchemical impurities such as sulphur, chlorine, nitrogen, and inorganicrefractory constituents. To facilitate the employment of the process inthese less than optimum circumstances various means of removal,neutralization and containment of the combustion byproducts from thefuel impurities are included in the invention. When practical these"undesirable" combustion byproducts may be converted into usablecommercial products.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the invention can be obtained when thedetailed description set forth below is reviewed in conjunction with theaccompanying drawings, in which:

FIG. 1 is a block flow diagram of an embodiment of the presentinvention;

FIG. 2 is a graphical representation of the effect of temperature on thespecific heat capacity of oxygen, carbon dioxide and water;

FIG. 3 is a graphical representation depicting the impact of waterinjection and recirculation upon the combustion process of the presentinvention;

FIG. 4 is a graphical representation of the impact of water injectionand recirculation gas on the percentage of carbon dioxide producedduring combustion;

FIGS. 5A and 5B depict a process flow diagram of a preferred embodimentof the present invention; and

FIGS. 6A and 6B depict a process flow diagram of the embodiment shown inFIGS. 5A and 5B with additional optional features.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIG. 1, the present invention is a process for combustinghydrocarbon fuels and recovering as much of the combustion product gasesas possible, thereby reducing or eliminating atmospheric discharge. Afuel stream is injected into primary combustion chamber 10 along with asubstantially pure oxygen stream and a water stream. The fuel, oxygen,and water streams are combusted in primary combustion chamber 10 and thecombustion product is then transferred to secondary combustion chamber12. In secondary combustion chamber 12, the combustion product isfurther combusted along with additional fuel, oxygen, and water streamsto produce a final reaction product stream. The reaction product streamis then introduced to an energy recovery boiler 14 or other means ofremoving and recovering heat energy from the reaction product stream.The cooled reaction product stream is then split with a portion of thecooled reaction product stream being recirculated to primary combustionchamber 10, a portion being recirculated to secondary combustion chamber12, and a portion proceeding forward to combustion gas cleaning system16. In combustion gas cleaning system 16, the cooled reaction productstream is treated to remove acidic components, residual organiccomponents, and finally to separate the water contained in the reactionproduct stream from the carbon dioxide. Carbon dioxide is thenintroduced into combustion gas recovery system 18 where it is purifiedand liquefied to produce a liquid carbon dioxide product. As will berecognized by those skilled in the art, implementation of thesecomponents of the present invention will reduce or eliminate the gasdischarge to the atmosphere.

Ideal complete combustion of a pure hydrogen fuel with pure oxygenyields carbon dioxide and water as the products of combustion. To insurehigh combustion efficiency, an excess of oxygen is required along withhigh temperature, high combustion gas turbulence, and long combustiongas residence time in the chamber(s) supporting the combustion process.These factors all contribute to contact opportunity between oxygenmolecules and molecules of hydrogen fuel(s) by producing robust mixingof the gases for long periods of time. The high temperature additionallyprovides the drive or ignition energy to produce the chemical reactionbetween the oxygen and fuel(s) when contact between molecules occurs.

Wagner teaches in U.S. Pat. No. 3,779,212 that a pure hydrogen fueloxidized with pure oxygen produces carbon dioxide, water, and carbonicacid as products of combustion. Wagner further teaches that the carbonicacid rapidly disassociates into carbon dioxide and water resulting inonly carbon dioxide and water as the ultimate products of the process.Wagner additionally teaches that the flame temperature associated withthe combustion of pure methane with pure oxygen can reach 6,000 degreesFahrenheit, (3,315.56 degrees Celsius). Wagner's invention is aspecialized boiler designed to maximize thermal efficiency with verysmall size and low weight per unit of energy derived. For refractorylined combustion chambers and standard energy recovery boiler systems,lower combustion gas temperatures are required. Typical refractorylimitations on continuous operating temperature are in the area of 2,500degrees Fahrenheit (1371.1 degrees Celsius). The present inventionutilizes pure oxygen for combustion, but additionally utilizes acombination of water injection and combustion gas recirculation tomoderate and control the combustion gas temperature achieved in thecombustion chambers.

The utilization of oxygen for combustion and water injection andrecirculated combustion gas to moderate combustion gas temperature avoidthe introduction of nitrogen into the combustion process. As taught byWagner, nitrogen in a combustion process leads to the formation ofpollution in the form of oxides of nitrogen (NOx). Since air is composedof roughly 80% nitrogen by volume, the present invention by designavoids the employment of air as the source of oxygen for combustion oras a means for moderating the combustion gas temperature in thecombustion chambers. Other reasons for avoiding use of air in thepresent invention are the fact that a high volume of combustion gaswould be produced per unit of fuel combusted and the resultingcombustion gas would contain a lower percentage of carbon dioxide makingcarbon dioxide recovery less efficient.

The following formulation and calculations detail the relationshipdiscussed above:

Combustion of methane with pure oxygen

CH₄ +2O₂ →CO₂ +2H₂ O

For each mole weight of methane two mole weights of oxygen are requiredfor stoichiometric combustion. One mole weight of methane equals 16atomic weight units while two mole weights of oxygen equals 64 atomicweight units. Each kilogram of pure methane then requires four kilogramsof pure oxygen for stoichiometric combustion resulting in 5 kilograms ofcombustion gas consisting of one mole weight of carbon dioxide and twomole weights of water. Carbon dioxide has a mole weight of 44 atomicweight units while water has a mole weight of 18 atomic weight units.The stoichiometric combustion of one kilogram of pure methane with pureoxygen then product (5×(44/80))=2.75 kilograms of carbon dioxide and(5×((2×18)/80)))=2.25 kilograms of water.

Typically, an excess amount of oxygen is supplied to a combustionprocess to provide greater opportunity for complete combustion of fuelsthan is afforded by a one to one stoichiometric ratio of oxygen to fuel.Depending on the fuel being combusted and the combustion processefficiency the typical amount of excess oxygen supplied is in the rangeof 5% to 10%. For this discussion and for ease of calculation consider a5% excess of oxygen for a practical combustion process. In such caseeach kilogram of pure methane would then require 4.2 kilograms of pureoxygen for combustion resulting in the production of 5.2 kilograms ofcombustion gas of which 0.2 kilograms is residual oxygen. By weightpercentage the combustion gas composition from this process would thenbe as follows:

Carbon Dioxide: (2.75/5.2)×100=52.88462%

Water: (2.25/5.2)×100=43.26923%

Oxygen: (0.2/5.2)×100=3.84615%

Using the known heating value of methane, calculated approximatespecific heat capacities for the combustion gas constituents, anapproximate ambient temperature and an approximate resultant combustiongas temperature can be calculated. The following relationship applies:

    T.sub.GAS =T.sub.AMB +((Q.sub.REL -Q.sub.LOSS)/C.sub.P)/M.sub.GAS)

Where T_(GAS) = Resultant Combustion Gas Temperature

T_(AMB) = Ambient Temperature

Q_(REL) = Thermal Energy Release Rate

Q_(LOSS) = Thermal Energy Loss Rate

C_(P) = Combustion Gas Specific Heat Capacity

M_(GAS) = Combustion Gas Mass Flow Rate

The published heat of combustion of methane is 21,520 BTU/LB (11,955.55Kilo Cal/Kilogram). This value takes into account the latent heat ofvaporization of the water produced in the combustion reaction and isapplicable for the above equation.

The heat capacity of a given gas varies with temperature and pressure.Working with a constant pressure the specific heat capacity withvariation due only to temperature can be derived, C_(P). For thisanalysis a constant pressure of one atmosphere may be assumed. Data areavailable for the gases of interest here at one atmosphere of pressureover the range of temperature to be encountered in a combustion process.C_(P) for these gases may be expressed as a polynomial function of theform, C_(P) =a₀ +a₁ T+a₂ T² +a₃ T³ =. . . a_(n) T^(n) where T is theabsolute temperature of the gas of interest. In the temperature range of0 to 2,500° F. the following fourth order polynomials with 99.0%confidence level have been derived for the atmosphere constant pressurespecific heat capacities of the noted gases:

    __________________________________________________________________________    Carbon Dioxide:            C.sub.P(CO2) =                  0.155989405 + 0.000194244567 (T) -                  5.69601423 × 10.sup.-8 (T.sup.2) + 2.64619520 ×                  10.sup.-13 (T.sup.3) +                  4.73867961 × 10.sup.-17 (T.sup.4) KCal/Kg-°K.    Oxygen: C.sub.P(O2) =                  0.194741234 + 9.17986378 × 10.sup.-5 (T) -                  3.60408938 × 10.sup.8 (T.sup.2) + 1.03017213 ×                  10.sup.-11 (T.sup.3) -                  3.13211436 × 10.sup.-15 (T.sup.4) KCal/Kg-°K.    Water Vapor:            C.sub.P(H2O) =                  0.378246954 + 0.0002190970339 (T) -                  7.65417026 × 10.sup.8 (T.sup.2) + 4.54506122 ×                  10.sup.-11 (T.sup.3) -                  1.22059215 10.sup.-14 (T.sup.4) KCal/Kg-°K.    __________________________________________________________________________

Where T is temperature in degrees Kelvin.

FIG. 2 graphically depicts the relationship noted by these calculations.

The specific heat capacity of a mixture of gases can be approximated byscaling each individual gas constituent specific heat capacity to thatconstituent's mass percentage of the mixture and summing the valuesderived. A mixture composed of 52.88462% carbon dioxide, 43.26923% watervapor and 3.84615% oxygen will then have a resultant specific heatcapacity as follows:

C_(P)(MIXTURE) =0.5288462 C_(P)(CO2) +0.4326923 C_(P)(H2O) +0.0384615C_(P)(O2)

These are the proportions calculated for the combustion gas producedfrom the complete combustion of methane with pure oxygen with a 5%surplus of oxygen being supplied. Knowing the amount of thermal energyreleased from the combustion reaction as sensible heat and the ambienttemperature at which the combustion gas constituents entered the processone can calculate both the specific heat capacity of the resulting gasmixture and the theoretical maximum combustion gas temperature.Considering that both the resulting gas temperature and the specificheat capacity of the gas mixture are interdependent variables, are-iterative process may be applied to calculate these parameters.

To avoid the high combustion gas temperatures noted by Wagner whileallowing the combustion process of the present invention to be used in apractical manner with standard combustion chamber construction andstandard energy recovery boiler equipment combinations of combustion gasrecirculation and water injection are utilized. Calculations have beencarried out to determine the appropriate quantities of combustion gasrecirculation and water injection required to achieve 2,500 degreesFahrenheit in the combustion chamber of the present invention. The datacharts and plots which follow detail the calculation results.

Table One below details the data derived from the calculations utilizedto produce FIG. 3.

                  TABLE ONE    ______________________________________    Relative Mass Flows For Methane-Oxygen Combustion    Water Injection & Recirculation To Maintain 2500 Deg. F.            Extra H.sub.2 O                       Recirc.            Injection  Mass    Total Mass    ______________________________________    Case One  6.426        0       11.626    Case Two  0            15.75   20.95    Case Three              1            12.492  18.692    Case Four 2            9.75    16.96    Case Five 3            7.32    15.52    Case Six  4            5.06    14.26    Case Seven              5            2.92    13.12    Case Eight              6            0.86    12.06    ______________________________________

Note from the calculations and plotted data derived therefrom thatcontrol can be exercised over the quantity of combustion gas generatedper unit of fuel mass combusted while maintaining a moderate combustiongas temperature. Utilizing a combination of water injection andrecirculation of cooled combustion gas the total mass flow of combustiongas out of the combustion chambers can vary from 20.95 to 11.626 massunits per mass unit of methane fuel combusted with 1.05 timesstoichiometric oxygen while maintaining 2,500 degrees Fahrenheitcombustion gas temperature. These calculations assume a 10% loss ofthermal energy through the combustion chamber walls. The lowestcombustion gas mass flow is achieved with zero combustion gasrecirculation and water injection alone utilized to moderate combustiongas temperature. The latent heat of vaporization of water is utilized toadvantage in this case as a means of minimizing mass flow per unit offuel mass being combusted. Under circumstances where this type ofoperation is favored the present invention can be so operated. Otherwisesome combination of water injection and cooled combustion gasrecirculation will normally be utilized as the means to controlcombustion gas temperature in the combustion chambers.

As shown in FIG. 4, the highest level of carbon dioxide in thecombustion gas occurs with zero water injection and recirculation ofcombustion gas alone being utilized to moderate combustion gastemperature. In this case the level of carbon dioxide will reach 52.88%of the total combustion gas production rate. The lowest level of carbondioxide in the combustion gas occurs with zero recirculation and waterinjection alone moderating the combustion gas temperature. In this casethe level of carbon dioxide will drop to 23.65% of the combustion gasmass out of the combustion chamber.

Energy absorbed as latent heat of vaporization into water is notrecovered in the energy boiler of the present invention. This is adisadvantage of water injection to moderate combustion gas temperature.An advantage of water injection in addition to the reduced combustiongas volume is the fact that a portion of the water can readily becondensed by cooling the combustion gases with a groundwater indirectheat exchanger prior to the inlet of the of the carbon dioxide recoverysystem. By condensing a portion of the water vapor carried as aconstituent of the combustion gas the gas volume is reduced and acleansing effect is achieved for the combustion gas. As water dropletsform during condensation, particulate matter and acidic constituentsthat might be carried in the gas due to less than ideal fuel compositionare efficiently removed from the gas with the condensate. With a higherpercentage of water and increased condensation, higher efficiency gascleaning is achieved. When utilizing fuels that contain acid producingconstituents and constituents that result in particulate matterformation water injection enhances the combustion gas cleansing processbetween the energy recovery boiler and carbon dioxide recovery system ofthe present invention and is included in the preferred embodiment forthat reason. Additionally, the present invention includes a provisionfor an optional electron beam oxidation reactor to enhance the overallcn combustion efficiency of the process. Water molecules produce OHradials and atomic oxygen when bombarded by accelerated electrons. Thesehighly reactive molecules act as scavengers for dilute concentrations ofresidual and reformed organic compounds in the post combustion chambercombustion gas stream. Included in the organic compounds that might bepresent in the post combustion chamber combustion gas stream are dioxinsand furans. Destroying these compounds to avoid contamination of theprocess effluents from the present invention is high priorityconsideration.

As shown in FIGS. 5A and 5B, the process of the present invention beginsby introducing a fuel stream 21, oxygen stream 22, and a water stream 24into primary combustion chamber 10 wherein the hydrocarbons from thefuel are combusted to produce the combustion product of carbon dioxide,water, and other combustion gases. Primary combustion chamber 10 has anash separation section 60 for removing a portion of solid componentsincluding ash that result from the combustion process. Combustionproduct 28 is then introduced into a separation cyclone 62 to removeadditional ash and solids. Separation cyclone 62 is of a varietycommonly known to those skilled in the art of combustion process. Havinghad the ash removed, combustion product stream 28 is then introducedinto secondary combustion chamber 20.

Preferably, secondary combustion chamber 20 is a vertical combustionchamber such as is known by those of ordinary skill in the art.Hydrocarbons from combustion product stream 28 are reacted with anadditional fuel stream 30, a second substantially pure oxygen stream 32,and a second water stream 34 in secondary combustion chamber 20. Fuelstreams 21 and 30 can be a variety of fuels, including methane and otherhydrocarbon-containing compounds. Solids, ash and other particulatematter are removed from a bottom cone section 64 of secondary combustionchamber 20. Reaction product stream 38 exits from the top of secondarycombustion chamber 20. Secondary combustion chamber 20 is included inthe process of the present invention to produce high combustionefficiency.

An important feature of the process of the present invention is theability to recover the energy, in the form of heat, from reactionproduct stream 38. Preferably, an energy recovery boiler 14 is used torecover the heat energy from reaction product stream 38. As thoseskilled in the art would recognize, energy recovery boiler 14 is used togenerate steam by transferring the heat energy from reaction product 38to a water stream. A portion of stream 38 can be used in parallel withenergy recovery boiler 14 to heat other process streams through crossexchanges of energy. Alternatively, other forms of heat exchangers canbe used to recover the heat energy from reaction product stream 38 inplace of energy recover boiler 14. Removal of the heat energy fromstream 38 in recovery boiler 14 results in a cooler stream temperature.Preferably, stream 38 is cooled to about 450 degrees Fahrenheit.

Cooled reaction product stream 40 is then introduced into a bag house 66for removal of particulate matter from cooled reaction product stream40. Bag house 66 is of a design commonly known and used by those skilledin the art. Preferably, an activated carbon injector 68 can be utilizedalong with bag house 66 to assist in removal of particulate matter.

Upon exiting bag house 66, cooled reaction product stream 40 isintroduced into combustion gas manifold 70. Fan 72 can be used toincrease the pressure of cooled reaction product stream 40 prior tointroduction into gas manifold 70.

In gas manifold 70, cooled reaction product stream 40 is split intothree streams. First stream 26 is recirculated to primary combustionchamber 10 to increase combustion efficiency. The amount ofrecirculating combustion gas introduced into primary combustion chamber10 can be controlled by control valve 74 or other means of regulatingstream volume. A second portion of gas is removed from combustion gasmanifold 70 and recirculated as gas stream 36 into secondary combustionchamber 20. The volume of gas flow from stream 36 is controlled by acontrol valve 76 or other means of regulating flow. Recirculation of gasstream 36 is introduced to secondary 03 combustion chamber 20 toincrease the efficiency of secondary combustion chamber 20.

The remaining portion of reaction product stream 40 exits combustion gasmanifold 70 as stream 42. Stream 42 is essentially the product streamfrom the combustion portion of the process of the present invention.Stream 42 comprises carbon dioxide, water, along with various otherimpurities and unreacted components from the combustion process. Stream42 is introduced into electron beam reactor 80 to break down residualdilute organic compounds contained within stream 42 and to impart anelectrical charge on any residual particulate matter in stream 42.Electron beam reactor 80 is of a variety commonly known and available tothose skilled in the art. Stream 42 exits electron beam reactor 80directly into ozone oxidation chamber 82 where additional components areoxidized and aid removal of them from the gas stream.

Next, stream 42 is introduced into an electrostatic precipitator andcatalytic reactor 84. In precipitator 84, additional particulate matteris removed from stream 42 including the particulate matter electricallycharged by electron beam reactor 80.

Stream 42 is next introduced into acid scrubber system 86 to remove anyremaining acidic constituents in the gas stream. Acid scrubber system 86comprises an adiabatic quench 88 and pack bed absorber 90. Acid scrubbersystem 86 is of a design commonly known to those skilled in the art ofpurifying gas streams. An alkaline stream 92 is contacted throughcountercurrent flow to pack bed absorber 90 to react away acidiccomponents found in stream 42. Optionally, acid scrubber system 86 mayconsist of a series of pack bed absorbers 90 to increase contactefficiency. The brine stream 94, which results from a contact of thealkaline stream 92 with the acid gas components, can then be filtered infiltration system 96. Stream 94 is then concentrated in distillationbrine concentrator 98 to produce, for example, a marketable 42% brinestream for use in downhole hydrocarbon production, particularlyfracturing operations.

Upon exiting acid scrubber system 86, stream 42 is increased in pressureby fan 100 and introduced into indirect heat exchanger 102. Indirectheat exchanger 102 is of a variety commonly known to those skilled inthe art of heat transfer. Preferably, ground water at approximately 55°F. is used to condense the water vapor from stream 42. The condensationof water vapor also removes most of any remaining forms of contaminationin the gas stream. Additionally, a condensate stream 104 comprising thewater and any residual contaminants is returned to acid scrubber system86 where it is combined with the brine.

Carbon dioxide stream 46 is then introduced into recovery system 18.Initially, stream 46 is introduced to a refrigeration heat exchanger108. Stream 46 then enters carbon dioxide recovery system 110 whereliquid carbon dioxide is separated from any excess oxygen or nitrogenremaining in stream 46. Carbon dioxide recovery system 110 is of adesign commonly known to those of ordinary skill in the art. As can beseen, liquid carbon dioxide stream 48 can then be marketed as a productto those needing carbon dioxide streams.

Finally, gas discharge stream 50 comprising excess oxygen and anynitrogen originally introduced through fuel streams 20 and 30 can bedischarged to the atmosphere. When operated under conditions such asdescribed herein, gas discharge stream 50 is eliminated or substantiallyreduced in comparison to prior art combustion processes.

FIGS. 6A and 6B discloses an adaptation of the embodiment of the presentinvention disclosed in FIGS. 5A and 5B. Particularly, the process ofFIGS. 6A and 6B has been adapted to include plasma torches 120 and 122and emergency evacuation chamber 124. Plasma torches 120 and 122 are ofa variety commonly known to those skilled in the art. Emergencyevacuation chamber 124 is an additional safety feature to enhance thesafety associated with the process of the present invention.

By utilizing pure oxygen for combustion and employing water injectionand recirculated combustion gas to moderate combustion gas temperaturein the combustion chambers the present invention allows all products ofcombustion to be captured before emission into the environment. Thecaptured products of combustion include carbon dioxide, water, andexcess oxygen. When nitrogen is present in the fuels being combusted amix of oxygen with a fractional trace of nitrogen will be removedtogether. Provision is made in the present invention to maintain thehighest possible combustion efficiency to reduce the level of traceorganic compounds in the combustion gas. Provision is also made toremove with the highest efficiency possible any acidic and particulateconstituents produced by the combustion of less than ideal fuels in theco combustion chambers of the present invention allowing the recoverycarbon dioxide and residual oxygen.

I claim:
 1. A process for combusting hydrocarbon streams and recoveringthe carbon dioxide produced during combustion, the process comprisingthe steps of:reacting a first hydrocarbon containing stream with asecond stream of substantially pure oxygen in a combustion chamber underconditions producing a reaction product stream comprising carbon dioxideand water vapor; removing particulate matter from the reaction productstream; separating the reaction product stream into a recycle stream andan intermediate product stream recycling the recycle stream into thecombustion chamber; subjecting the intermediate product stream toelectron beam oxidation to breakdown residual organic compounds and toelectrostatically charge residual particulate matter; removing theelectrostatically charged particulate matter from the intermediateproduct stream; scrubbing the intermediate product stream to neutralizeand remove acidic impurities; condensing water vapor from theintermediate product stream; and refrigerating the intermediate productstream to condense any remaining water and to liquefy the carbondioxide.
 2. The process of claim 1, wherein the scrubbing step comprisesscrubbing the intermediate product stream with an alkaline solution andthereby generating a brine solution.
 3. The process of claim 2, furthercomprising the steps of: filtering the brine solution to removeimpurities; and concentrating the brine solution.
 4. The process ofclaim 3, wherein the brine solution is concentrated to about forty-twopercent brine.
 5. The process of claim 1, wherein the reacting stepfurther comprises introducing a water stream into the combustionchamber.
 6. The process of claim 1, wherein the reacting step occurs intwo stages, a first stage comprising reacting a first hydrocarboncontaining stream with a first stream of substantially pure oxygen in afirst combustion chamber, and a second stage comprising reactinguncombusted components from the first stage and a second hydrocarboncontaining stream with a second substantially pure oxygen stream in asecond combustion chamber.
 7. The process of claim 6, wherein therecycling step further comprises recycling a portion of the recyclestream into the second combustion chamber.
 8. The process of claim 1,wherein after the reacting step, the process further comprises a step oftransferring heat energy from the reaction product stream to a boilerfor generating steam.
 9. The process of claim 1, wherein after thereacting step, the process further comprises a step of transferring heatenergy from the reaction product stream to a stream from a secondprocess requiring heat input.